Electric burglar alarm



" (N0 MOfleL) 3 Sheets-Sheet 1. H. ROHRDANTZ.

ELEGTRIG BURGLAR ALARM.

No. 562,325. Patented June 16, 1896.

ll 6 x w n Il, r

. l. JC fil; l 7i l l I l /15 JL l Il Jr f* 1 t 1 l V f'M/l J l l" M 5 ll'z/ L' Jl ll l r Il e Ef ff 'J9' l l Y l e n I O J2 J J), 1 E f' f Q' f I.' 1=l= Q l I l I l B c' 9 "/"f""/" l Jf/ 41%..;

fla"

ANDREW E GRAHAMPNUTDLITMO WASMINGTUN DC 3 Sheets-Sheet 2.

(No Model.)

H ROHRDANTZ BLBGTRIG BURGLAR ALARM.

Patented June 16, 1896.

vvuemfoz (No Model.) 3 Sheets-Sheet 3. N H. ROHRDANTZ.

ELECTRIC BURGLAR ALARM.

No. 562,325. Patented June 16, 1896.

@MMM/wooo@ S14/ven tot www M4, @13

ANDREW BvGRAHAMyHOTO Lmm WASHINGmNDC UNITED A STATES PATENT OEEICE.

HENRY ROHRDANTZ, OF BUFFALO, NEW YORK.

ELECTRIC BURG LAR-ALARM.

SPECIFICATION formingpart of Letters Patent No. 562,325, dated June 16, 1896. Application filed January 30, 1896. Serial No. 577,454. (No model.)

T0 @ZZ whom, t may concern:

Be it known that I, HENRY ROHRDANTZ, of

Buffalo, in the county of Erie and State of New This invention pertains to electric burglar` alarms; and it consists in the several mechanical devices and arrangements hereinafter fully described, as also the circuits and connection whereby the same are set in motion by circuit-closers arranged at the doors and windows of houses or at other points where they may be operated by burglars.

Some of the primary objects of the present invention are to provide an electrically-operated detonating alarm of improved construction, to provide atime mechanism of improved form for actuating the detonating devices in various parts of the house in close succession or at longer intervals if desired, to provide an improved electromagnet-trip for the time mechanism, and also to provide a circuit-breakerof improved form for cutting out the electromagnet after the time mechanis-m has been tripped.

Referring to the accompanying drawings, Figure l is a diagrammatic view of my improved burglar-alarin system, the same showing the several portions of the invention set but not tripped. Fig. 2 illustrates the time mechanism in an operative position after being tripped. Fig. Sis an elevation of the detonating mechanism in firing position. Fig. e is a perspective view of the time mechanism shown partly in section and with the frame carrying the dial and contacts set out therefrom to afford better illustration. Fig. 5 is a view of a portion of the detonating mechanism with the barrel turned to one side for loading.

The system herein shown and described involves the maintenance of two distinct battery-circuits, each circuit having its subcircuits. One of the battery-circuits is for the purpose of setting in motion the time-trip when the said circuit has been closed by the opening of a door or window. Said circuit may also be used for actuating an ordinary alarm-bell. The other battery-circuit connects the time-trip andthe detonating alarms and serves when closed to discharge the latter at the desired intervals of time.

I will now proceed to describe the circuit which sets in motion the time-trip and also the mechanisms arranged in said circuit and its various connections.

A designates a circuit-closing device arranged in a door-casing and which is closed by the opening of the door A. Circuit-wire B, connected to one post of the circuit-closer A, leads to post a of switchboard C and from thence to post Z2' of switch l) on said board. From thence the circuit B leads through posts d and c to battery D. Circuit-breaker b is for the purpose of disconnecting the circuit from the doors and windows when so desired. Vire B leads from the other post of circuitcloser A up the binding-post e of the electromagnet E, and from thence through post e to post f, which securesthe spring-plate F. The free end of plate F bears against the end of the spring-plate F', and from the bindingpost f of said last-named spring-plate the wire B extends to post d of switchboard C, and from thence to post CZ', and the lastnamed post is connected by the swinging circuit-closing plate Gto post g. From thence the circuit-wire extends to post g', and from the last-named post to the battery D, thus completing the circuit of wires B l5.

Armature E" of the electromagnet E is hooked at its lower end, as indicated at E", and adapted to be supported by said hooked end is the laterally-projecting plate Il, secured to the lower end of the vertically-movable rod H'. The said rod is thus supported in a raised position and when thus held engages the escapement of a time mechanism and holds the same away from actuating closing devices in the alarm-circuit. Now when circuit B B is closed the electromagnet will be energized and the armature E will be drawn thereto, thereby removing the support for the vertically-movable rod H and permitting the same to drop, and thus remove the obstruction to the time-trip and permit it to operate. The outer extremity of IOO spring-plate F' also bears upon the latter projection H of the rod Il', so that when-the rod is in a raised position the said plate is raised in contact with spring-plate F, but as soon as rod H drops, the support for plate F' is removed and the contact between the same and the spring-plate F is broken, as shown in Fig. 2, thus breaking the circuit B B', which is no longer needed, as the time-trip has been set in motion. Battery D is thus saved from uselessly exhausting itself.

If so desired, the electromagnet-trip mechanism may be cut out by the turning of the plate G, as indicatedin Fig. l, in dotted lines, and the circuit used simply for operating an electric alarm-bell I, positioned in any part of the house desired and brought into the circuit by wires t and t'.

A clock mechanismJ is positioned at a convenient point in the house and is included in the battery-circuit K K', which also includes the alarm presently to be described. An auX- iliary frame J', carrying a dial, is arranged adjacent the clock-case, but insulated therefrom, and into it extends the central arbor j, and on said arbor is hand j', which is adapted to make a complete revolution every hour.

L are circuit-closing points fixed on arbor j within case J', three of said points bein g here shown, and each point is adapted to contact with an outwardly-pressible spring-arm M, carrying roller M' at its free end, which projects through the casing so as to be reached by the pointer. From each arm M leads wire K', through which the circuit is closed to the alarm device, the latter being positioned in different parts of the house. The middle or upper pointer L has rotation corresponding with hand j'. The roller M' of arm M, positioned on top of casing J', is directly over the dial-ordinal 12, so that as soon as hand j' and corresponding pointer L reach that point, as in Fig. 2, the circuit is closed and the alarm sounded. The relative position of the other ointers L is preferably such that the one to the right of the pointer above mentioned will engage roller M' and close the circuit one minute after the first alarm has sounded, while the pointer at the left of the casing will close the circuit two minutes after the first alarm, thus sounding alarms which may be arranged at different points in the house, at intervals of one minute. The preferred setting of the mechanism is shown in Fig. l, where the upper pointer is set one minute ahead of its circuit-closing spring, so as to sound the first alarm one minute after the house has been entered and rod H' disengaged from the escapement, the second alarm two minutes after, and so on. It will be understood, however, that the circuit-closing devices may be arranged to discharge in any other order desired, or simultaneously. The contact between pointers L and the rollers lV is very slight, so as not to impede the progress or movement of the former, while at the same time the contact is sufficient to close the circuit and cause the alarm devices to be operated.

A circuit-breaker 7c is arranged in the circuit K K' for the purpose of cutting out the alarm devices whenever desired either for the purpose of repairing the tripping mechanisms, the time mechanism, or in handling any portion of the alarm system which might accidentally cause the discharge of the alarm devices.

Each alarm consists of a barrel pivoted centrally upon its under side, so as to swing laterally, as in Fig. 5, for the purpose of convenient loading, and when turned back to position is held by locking-pin N directly in line with the firing-pin O, the latter being actua ted by hammer P, pivotally mounted at its upper end as shown. From the upper end of the hammer extends the lug p, which is adapted to be engaged by the strong spring P' for the purpose of throwing the hammer with great force against Athe ring-pin when the hammer has been released. Upon the inner side of the hammer is formed a slight offset or shoulder p', which is normally engaged by trip Q, forming an integral part of armature Q', and which when in engagement with said shoulder serves to hold the hammer drawn backward ready for firing. An electromagnet R is arranged in the circuit K K', and when the same is energized the armature is drawn upward, thus releasing the hold of trip Q upon the hammer, when the latter will be thrown against the firing-pin with great force by spring P', thus causing theblank cartridge within the barrel to discharge with a loud report. This operation will be repeated as many times as there are alarm devices in the circuit.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The combination of a motor,circuitwires K, K', connected thereto, one wire being insulated therefrom, spring-arm M extended from the insulated Wire, roller M' on the extremity of said arm, and a circuit-closer adapted to be rotated by the motor and to contact with roller M' which projects slightly in its path, the roller serving to pass the circuit-closer by slight deiiection of the springarm Without stopping the motor, substantially as shown and described.

2. An alarm system including an electrical circuit, a circuit-closer therein at an exposed point in the house, an electromagnet within the circuit, the armature for the magnet held normally therefrom and provided with the angular extension at its end, an alarm device, the vertically-movable rod adapted to normally hold the alarm device from operation, the plate carried by the lower end of the rod adapted to rest upon the angular projection of the armature when the latter is in its normal position, the circuit-breaker consisting of the spring-plates F, F', which are caused to engage each other by resting upon the said IOO IOS

IIO

cocked when the armature is away from the magnet, and a spring for forcing the hammer to tiring position when the armature is moved from engagement with the hammer by being drawn to the magnet when the electrical circnit is closed, substantially as shown and described.

ln testimony whereof l aix my signature in presence of two witnesses.

HENRY ROHRDANTZ. lVitnesses:

FRED W. PLATO, FRANK A. HEBELER. 

